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Oct. 13, 1931. 0115 EFFECTIVE TEMPERATURE CONTROL APPARATUS I Filed Sept. 28, 1928 ladenfoi} Get-old. ELOhs B 7 g X 4 Lmga.

Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE GERALD E. OTIS, OF MOLINE, ILLINOIS, ASSIGNOR TO THE HERMAN A CORPORATION OF ILLINOIS 'IION, OF MOLIN E, ILLINOIS,

NELSON CORPORA- EFFECTIVE TEMPERATURE CONTROL APPARATUS Application filed September 28, 1928. Serial No. 309,048.

The primary object of this invention is to provide improved means for conditioning the atmosphere in auditoriums and similar p aces in warm weather, in so far as temperature and relative humidity are concerned.

. humidified air to neutralize nance.

air is passed through It is well understood in the art that in order to maintain a comfortable condition in spaces occupied by people in warm weather, it is necessary to circulate pre-cooled and dethe eflect of body heat and moisture given off by the occupants.

In the older art, attempts were made to precool and de-humidify the air by passing it over coils in which a refrigerant such as cold brine was circulated. However, this scheme did not prove generally practical, due to the collection of frost on the coils and to lack of proper humidity control. At the present time, a method is in common use whereby the chilled water sprays. This does away with the trouble from frost and also permits of a more or less satisfactory means for humidity regulation. Since in this process the air leaves the spray chamber practically saturated with moisture, and it is a law that the amount of moisture in saturated air is fixed by its temperature, the humidity can be controlled by regulating the temperature at which the air leaves the spray chamber through thermostatic means.

The equipment used in present practice is expensive, requires considerable space and a great deal of attention and cost of. mainte- Where the temperature is regulated through by-passing air, satisfactory humidity control cannot be secured without continual readjustment of the dew-point temperature to meet varying load conditions. If reheaters, were used, a continual loss would be involved under average load conditions, due to the fact that the air must be saturated in order to chill it to the desired degree to de-humidify it.

The object of my invention affords more simple, compact, and less expensive equipment, as well as more accurate control.

Two banks of radiators are employed. ,The

first, in which a refrigerant such as cold brine is circulated, cools the air and condenses the excess moisture. The second, in which a heating medium such as hot water is used, reconditions the air as to temperature. In order to sufficiently de-humidify, it is usually necessary to cool the air to a temperature lower than that at which it is safe to deliver it into the auditorium, and it is therefore necessary to provide means for reheating. de-humidifying is rendered practical and preferable to water sprays through the discovery which I have made, that radiators constructed with a large number of comparatively long, thin plates, and exposing little prime surface, do not frost under conditions prevailing in this class of work. The plates may be built of highly conductive non-corrosive metal, such as copper or aluminum, and very closely spaced. The air passages should be ably smooth.

In the radator illustrated, which I have successfully used in practice, the plates are about four and a half inches wide, eight inches long, and .03 inch thick, and are spaced five to the inch. The core has a'mean all thickness of about one inch. It is cast of an aluminum allo while the plates are of pure sheet aluminum. This radiator is the subject of another patent application, Serial N 0. 646,7 7 6, by Otis and Shurtlefi', filed June 21, 1923,Radiator for heating purposes.

Improved means of automatic temperature and humidity regulation are secured through the use of a humidostat and a thermo'stat, both suitably located in the auditorium so as to properly register the mean atmospheric condition in the occupied zone and over The use of radiators for cooling'and' Y operating respectively to control valves on .,the lines supplying brineto the cooling radiators and hot water to the reheating radiators, as will be readily understood by those skilled in the art.

l/Vhen the relati vehumidity of the atmosphere in the auditorium falls below a predetermined point, the humidostat will throttle the brine supplied to the cooler. This will re sult in a higher brine temperature within the radiators, a higher temperature of the air passing-over the radiators, and consequently less condensation, which will cause the humidity in the auditorium to rise. When the relative humidity exceeds the predetermined point, the brine control valves will open with the opposite effect.

In the meantime, should the temperature of the auditorium rise above a predetermined point, the thermostat will throttle the valves controlling the hot water supply to the reheaters, thus lowering the temperature of the air delivered to the auditorium, and consequently the temperature in the same. Should the temperature fall, the reverse action will take place.

Further refinements of control can be secured by the use of relays, as is now understood in the art. For instance, under certain conditions, should the control valves on the reheater be completely closed and the air be so dry that the humidostat tends to restrict the action of the cooler with a resulting discharge of uncooled air therefrom at a temperature which would overheat the auditorium, a relay can be provided that will prevent the control valves on the cooler from closing so far as to allow the room temperature to become excessive.

On the other hand, should the temperature in the auditorium tend to drop below the desired point when the control valves on the reheaters are wide open, a relay can be arranged to control the original source of heat so as to increase the temperature of the hot watersupply to the radiator. manner, should the air tend to be too moist when the control valves on the cooler are wide open, a relay can be provided controlling the original refrigerating source so as to lower the temperature of the brine.

Further objects and details will appear from a description of the invention in con junction with the drawings, wherein Figure 1 is a diagrammatical view illustrating the principles of the present invention; an

Fig. 2 is a sectional perspective view of one of the radiators of the type preferably employed in conjunction with the present invention.

In the diagrammatic View, the auditorium, theater, or other place of assembly 10, is cooled and ventilated by the apparatus 11, which, as shown, comprises a casing 12 which admits air to the room through a port 18. The casing is provided with a cooling radiator 14 and a heating radiator 15, arranged, as shown, in tandem relation to one another. A fan 16 is employed to force air through the casing and discharge the same into the room after passage through the cooling and heating radiators. The air admitted to the ,fan may be drawn from an outside source,

or from an inside source, or, as is commonly the case, from both sources, in any desired volumetric ratio.

The radiator 1lis preferably of the type In a similar 'cooling and heating rsaaoee shown in Fig. 2, and illustrated and described in greater detail in the application aforesaid. The radiator 15 may be of the same type, although any radiator will serve the purpose for which radiator 15 is employed. The radiator 14 (and 15 if desired) comprises ahollow core 17 which extends through a plurality of closely spaced radiating fins or plates 17, which are preferably constructed of a metal of high thermoconductivity, such as pure aluminum, so that the radiator will possess very high radiating capacity in ratio to its size, which is important in the employment of chilled brine for cooling purposes, in that it prevents the deposition of layers of frost of excessive thickness on the surfaces exposed for radiation, which is a condition commonly experienced in the use of coils or radiators of conventional type which quickly become coated with frost to such a degree as to impede 'the free circulation of the air.

A cooling liquid, such as brine, is admitted to the radiator 1 1 through a pipe system represented by 18; and a heating medium, such as hot water, is admitted to the heating radiator 15 through a pipe system represented by 19. It is not deemed necessary to specifically describe the pipe arrangement, which may be of any usual and well 'known character, although, in view of the slight heating load required on the radiator 15, it may be convenient and economical to employ the hot condenser water at a temperature of about 90. 0f course, in cases where steam is available, a reduced reheating surface only will be required and a large percentage of the air may be bypassed beyond the heating radiator in a manner Well known and understood in the heating art.

Tn order to automatically regulate the coils, regulating devices 20 and 21 are applied respectively to the cooling and heating pipes 18 and 19. The regulating device 20, which controls the flow of the cooling medium, is controlled by a humidostat 22 which is responsive to changes in the humidity of the air in the auditorium 10; and likewise, in order to control the flow of the heating medium, the regulating device 21 is controlled by a thermostat 23 in the auditorium.

After a determination has been made of the desired conditions of humidity and temperature torium, the humidostat and thermostat respectively are adjusted to maintain ditions, and the apparatus wili th i Y automatically to maintain the ordinary type of to he maintained within the audia the relay given off by occupants in the room.

It is, of course, possible to secure a proper relation between the humidity and inside temperature, by cooling a portion of the air to a low degree to eliminate moisture,

and thereafter to mingle the cool air with a proper volume of uncooled air prior to the discharge of the mixture into the auditorium. This method eliminates the necessity for using a heating radiator, but it is objectionable for the reason that it imposes an excessive load on the cooling radiator in order to reduce the water content of the cooled air sufliciently to compensate forthe retention of the water content in the air which is recirculated without cooling.

By employing a heating coil'in conjunction with a cooling coil, all of the air can be passed through the two coils in succession, and sufiicient of the water content removed by lowering'the dew-point to meet the intended requirements, after which the temperature of all the air can be raised by heating to the degree required to produce the desired temperature in the auditorium.

This requires only a moderate re-heating, so that the load of the heating element of the present system will ordinarily be a light one during the hot weather period when air cooling 'is desired. At the same time, by automatically controlling heating elements, a more perfect regulation of the conditions can be maintained than would otherwise be the case.

' If it is desired to provide for conditions in which theair at the temperature required in the auditorium is abnormally dry, so that the humidostat, unless its action; be disabled or counteracted, will completely shut off the brine flow through the cooling .coil, and hence prevent a beneficial cooling effect in maintaining comfortable conditions, the following devices are employed:

A reverse acting thermostat pilot relay 24 is led into the air line 26 leading to the humidostat 22, which relay is of a type well known in the art and designed to open a leak in the air line when the temperature rises to a predetermined point, so that with temperature the action of the humidostat under excessively dry conditions will be ineffective at undesirably high temperatures to i completely shut ofi' the flow of'brine through both the cooling and adjusted to the desired degree of the cooler, with the result that the latter will continue to function in cooling the air rather as a temperature regulating agent than in its usual capacity asa de-humidifier.

Compressed air from a common source is admitted through a pipe line 25 to the air lines 26 and 27 respectively, restrictors 28 and 29 being interposed to restrict the flow of air to the thermostat 23 and the humidostat 22.

In cold weather, where air cooling is not required, the heating radiator may be employed to full capacity for heating purposes, and the cooling radiator may be thrown out of commission.

I claim:

1. In temperature control mechanism in combination with the room to be conditioned,

air conditioning means 'comprisinga cooling unit for varying the temperature of the incoming air and a heating unit, means for directing all of the air first through the cooling unit and afterwards through the heating unit, and finally into the room controlling means within the room for regulating the cooling capacity of the cooling unit. temperature responsive means within the room adapted when the room temperature rises above a predetermined point to disable the action of the said controlling means, and controlling means within the room for regulating the heating capacity of the heating unit.

2. In temperature control mechanism in combination with the room to be conditioned, air conditioning means comprising a cooling unit for varying the temperature of the incoming air and a heating unit in tandem relation with one another, a fan for directing air successively through the cooling unit and the heating'unit, to first lower the dew-point of the air to the degree required to partially remove the water content, and then to heat the air to the desired temperature for admission to the room, valve means for admitting a cooling agent to the cooling unit, valve means for admitting a heating agent to the heating unit, a humidostat within the room having pneumatic connection with the valve for the cooling unit, for controlling the operation of said valve in admitting a cooling agent. to the cooling unit in response to variations in the water content of the room temperature, a thermostatic pilot relay in communication with the pneumatic connection for the humidostat and adapted, Whenthe room temperature rises above a predetermined point, to open a leak in the air line and thereby disable the effective operation of the humidostat in closing the valve of the cooling unit, and a thermostat in the room for controlling the valve of the heating unit in response to variations in the room temperature.

3. In an air conditioning system of the lac class described, the combination of a room in which. the air is to be conditioned; means for delivering air to said room, comprising a blower a conduit. a variable coolin unit and a variable re-heating unit in sai conduit through which the air passes, a humid ostat in the room responsive to humidity conditions therein for controlling said variable cooling unit to de-humidify the incoming air, thermostat means within the room responsive to temperature variations for controlling said re-heating unit to raise the temper: ature of the incoming de-humidified air to the proper point, and means responsive to abnormal room conditions for rendering said humidostat and thermostat controlling means inefiective.

i. in an air conditioning system of the class described, the combination of a room to be conditioned; a de-humidifying cooling unit and a tem erature regulating heating unit arrange in tandem relation, a blower for forcing air first through said dehumidifying unit and then through said reheating unit; a humidostat within the room responsive to air conditions therein for controlling said de-humidifying unit to reduce the incoming air temperature belovv'that required in the room; a thermostat responsive to temperature conditions in the room for controlling the re-heating unit to re-heat said cooled air to the temperature required in the room; and means responsive to air abnormal conditions in the room for rendering said humidostat and thermostat controlling means inefiective.

ln witnessthat 1i claim the foregoing I have hereunto subscribed my name day of September, 1928.

GERALD E. OTIS.

this 25th 

